Genetic Evaluation of the Patients with Clinically Diagnosed Inborn Errors of Immunity by Whole Exome Sequencing: Results from a Specialized Research Center for Immunodeficiency in Türkiye.

Molecular diagnosis of inborn errors of immunity (IEI) plays a critical role in determining patients' long-term prognosis, treatment options, and genetic counseling. Over the past decade, the broader utilization of next-generation sequencing (NGS) techniques in both research and clinical settings has facilitated the evaluation of a significant proportion of patients for gene variants associated with IEI. In addition to its role in diagnosing known gene defects, the application of high-throughput techniques such as targeted, exome, and genome sequencing has led to the identification of novel disease-causing genes. However, the results obtained from these different methods can vary depending on disease phenotypes or patient characteristics. In this study, we conducted whole-exome sequencing (WES) in a sizable cohort of IEI patients, consisting of 303 individuals from 21 different clinical immunology centers in Türkiye. Our analysis resulted in likely genetic diagnoses for 41.1% of the patients (122 out of 297), revealing 52 novel variants and uncovering potential new IEI genes in six patients. The significance of understanding outcomes across various IEI cohorts cannot be overstated, and we believe that our findings will make a valuable contribution to the existing literature and foster collaborative research between clinicians and basic science researchers.

A Rare Autoimmune Disease Detected in the Differential Diagnosis of Immunodeficiency: Histiocytosis-lymphadenopathy Plus Syndrome.

Mutations in the SLC29A3 gene cause histiocytosis-lymphadenopathy plus (H) syndrome, a rare autosomal recessive genetic condition that affects numerous systems. We present a 7-year-old Syrian patient with pericardial effusion whose acute phase reactants did not decrease despite treatment. In order to emphasize the variety and raise awareness of H syndrome in the hopes of achieving an early diagnosis and appropriate treatment, molecular investigation of SLC29A3-related disorders is crucial. H syndrome is an uncommon genetic condition with a broad spectrum of phenotypes. Therefore, early genetic testing is essential for the accurate diagnosis of patients. Doctors should be aware of this condition and its symptoms and consider autoimmune diseases as a possible alternative diagnosis in patients with suspected immunodeficiency.

Association of childhood asthma with Gasdermin B (GSDMB) and Oromucoid-like 3 (ORMDL3) genes.

OBJECTIVE: Genome-length association studies have shown that Gasdermin B (GSDMB) and Orosomucoid-like 3 (ORMDL3) genes located on the long arm of chromosome 17 are associated with asthma. In this study, it was aimed to determine the possible relationship between asthma control test (ACT), exercise provocation test (ECT), and fractional nitric oxide (FENO) levels and GSDMB and ORMDL3 gene expressions. METHODS: 59 asthmatic and 38 non-asthmatic children were included in the study. We divided the patient group into two subgroups as mild persistent asthma (29 patients) and moderate persistent asthma (30 patients). ORMDL3, GSDMB gene expression levels, ECT, total IgE levels, and eosinophil counts were measured in all cases. In addition, ACT and FeNO levels were measured in children with asthma. Afterward, the relationship of ORMDL3 and GSDMB gene expression coefficient changes with ECT, ACT, and FeNO was examined. RESULTS: When patients with ACT ≤15 were compared with patients with ACT ≥20, ORMDL3 and GSDMB gene expressions were increased 6.74 and 11.74 times, respectively. Comparing patients with ACT ≥20 and ACT ≤15 in terms of coefficient changes (ΔCq), higher change values were observed for ΔCq ORMDL3 in patients with ACT ≤15 (p=0.015). Similarly, when patients with FENO ≤25 ppb were compared with patients with FENO >25 ppb, ORMDL3 and GSDMB gene expressions were increased by 2.93 and 3.56 times, respectively. When the coefficient changes were compared, no significant difference was found between FENO≤25 and FENO >25 patients. There was a slight negative correlation between ΔCq values and ACT score (p=0.003, r=-0.418 for ORMDL3, and p=0.016, r=-0.345 for GSDMB). In addition, we observed a statistically significant positive correlation between ORMDL3 and GSDMB gene expressions (r=0.80, p<0.001). CONCLUSION: We showed that increased ORMDL3 and GSDMB gene expression levels may be associated with ACT scores, FeNO and ECT in asthma. These findings may encourage future studies with larger numbers of subjects that can use gene expression levels in various asthma phenotypes for prognostic prediction.

The success of the Cystic Fibrosis Registry of Turkey for improvement of patient care.

BACKGROUND: Cystic fibrosis (CF) registries play an essential role in improving disease outcomes of people with CF. This study aimed to evaluate the association of newly established CF registry system in Turkey on follow-up, clinical, growth, treatment, and complications of people with this disease. METHODS: Age at diagnosis, current age, sex, z-scores of weight, height and body mass index (BMI), neonatal screening results, pulmonary function tests, history of meconium ileus, medications, presence of microorganisms, and follow-up were evaluated and compared to data of people with CF represented in both 2017 and 2019 registry data. RESULTS: There were 1170 people with CF in 2017 and 1637 in 2019 CF registry. Eight hundred and fourteen people were registered in both 2017 and 2019 of whom z-scores of heights and BMI were significantly higher in 2019 (p = 0.002, p =0.039, respectively). Inhaled hypertonic saline, bronchodilator, and azithromycin usages were significantly higher in 2019 (p =0.001, p = 0.001, p = 0.003, respectively). The percent predicted of forced expiratory volume in 1 sec and forced vital capacity were similar in 2017 and 2019 (88% and 89.5%, p = 0.248 and 84.5% and 87%, p =0.332, respectively). Liver diseases and osteoporosis were significantly higher, and pseudo-Bartter syndrome (PBS) was significantly lower in 2019 (p = 0.011, p = 0.001, p = 0.001, respectively). CONCLUSIONS: The z-scores of height and BMI were higher, the use of medications that protect and improve lung functions was higher and incidence of PBS was lower in 2019. It was predicted that registry system increased the care of people with CF regarding their follow-up. The widespread use of national CF registry system across the country may be beneficial for the follow-up of people with CF.

Exhaled TGF-ß1 levels before and after an exercise challenge in asthmatic and healthy children, and during exacerbation.

BACKGROUND: There is conflicting data regarding the role of transforming growth factor-ß1 (TGF-ß1) in the pathogenesis of airway hyper-reactivity and asthma exacerbation. OBJECTIVE: To investigate the role of exhaled-TGF-ß1 in exercise-induced bronchospasm (EIB) in asthmatic and nonasthmatic healthy children, and in asthma exacerbation and asthma control. METHODS: The exhaled-TGF-ß1 levels of 56 stable asthmatic children and 15 nonasthmatic healthy children were evaluated before and 30 min after an exercise challenge. The exhaled-TGF-ß1 levels of 20 additional children with asthma exacerbation were evaluated. RESULTS: While no significant difference in the exhaled-TGF-ß1 levels was found at the baseline, exhaled-TGF-ß1 levels after the exercise challenge were significantly higher in the non-EIB (n = 31) asthmatics when compared to the asthmatic children with EIB (n = 25) (p = 0.04). Although there was a statistically significant increase in the concentration of the exhaled-TGF-ß1 after the exercise challenge in the non-EIB asthmatics (p = 0.008), the concentration of the TGF-ß1 was not increased after the exercise challenge in EIB + asthmatics. The exhaled-TGF-ß1 was significantly correlated with the ACT score (p = 0.01, r = 0.49) and the baseline FEV1 level (p = 0.02, r = 0.35). The exhaled-TGF-ß1 levels were significantly higher in the stable asthmatic children when compared to the nonasthmatic children (p < 0.0001). There was no significant difference in exhaled-TGF-ß1 levels after the exercise challenge in the nonasthmatics. The exhaled-TGF-ß1 levels were significantly lower in those children with asthma exacerbation when compared to the stable asthmatic children (p = 0.0003). CONCLUSION: Our results suggest that TGF-ß1 may play a role in suppressing airway reactivity and its deficiency is associated with asthma exacerbation.

A hereditary angioedema screening in two villages, based on an index case, and identification of a novel mutation, "1033G>T", at the SERPING1 gene.

INTRODUCTION: Hereditary angioedema (HAE) may be fatal and diagnosis can be delayed up to 10 years. We aimed to screen HAE in two villages based on an index case of HAE and to investigate for the mutation of the C1 esterase inhibitor (C1-INH) gene. MATERIAL AND METHODS: A total of 124 people were screened in two villages. The frequency and severity of symptoms were scored. C4, C1-INH levels and C1-INH activity were measured. We investigated for mutations of the C1-INH gene. RESULTS: Thirty-five cases of type I HAE and 7 cases of type II HAE were determined. Thirty-one (73.8%) patients diagnosed with HAE were 18 years old or younger. There was a positive correlation between C4 levels, C1-INH levels (p < 0.0001, r = 0.81), and C1-INH activity levels (p < 0.0001, r = 0.631) and between the age at diagnosis and severity score (p < 0.0001, r = 0.651). A positive correlation was found between the age at first symptom onset and C4 levels (p = 0.002, r = 0.774), and C1-INH levels (p = 0.006, r = 0.714). A marginally significant negative correlation was found between C1-INH activity levels and severity scores (p = 0.1, r = -0.515). We identified a novel heterozygous 1033G>T missense variant of the C1-INH gene, SERPING1, in patients with type I HAE. CONCLUSIONS: There are long delay periods in the diagnosis of HAE and when the index case is present, family screening may be very important and even life-saving, in particular, in paediatric patients without symptoms. Furthermore, the present study provides evidence to link a novel mutation, c.1033G>T, to the development of HAE in a large HAE family from Turkey.

A hereditary angioedema screening on an index case: Turkey.

BACKGROUND: Hereditary angioedema (HAE) is characterised by recurrent episodes of angioedema and can be fatal. OBJECTIVE: The present study aimed to screen HAE. METHODS: A total of 60 individuals were screened. The frequency and severity of symptoms were scored from 0 to 8. Measurements were taken of C4 and C1 esterase inhibitor protein (C1-INH) levels. Mutation in the C1 inhibitor gene was examined in 9 patients with HAE. RESULTS: A positive correlation between the C1 esterase inhibitor protein levels and C4 level was detected in the group as a whole (p < 0.001, r = 0.725, n = 60). Anegative correlation between the C1 esterase inhibitor protein level and severity score was observed in the whole group (p < 0.001, r = -0.486, n = 60). A negative correlation was also detected in the entire group between the C4 level and severity score (p = 0.002, r = -0.389, n = 60). In the patients with HAE, a positive correlation between the C1 esterase inhibitor protein level and C4 levels was detected (p = 0.034, r = 0.705, n = 9). A heterozygous c. 601A > T nonsense variant was identified at the C1 esterase inhibitor gene-SERPING1-in patients with Type 1 HAE. CONCLUSION: It is well known that there is a prolonged delay in the diagnosis of HAE. The present study demonstrates that it is very important and even life-saving to screen for HAE on the basis of an index case.

The relationship between serum vitamin D level and asthma.

OBJECTIVE: Several studies have established a relationship between low serum vitamin D levels and the onset of asthma in childhood. In this study, we aim to assess the relationship between vitamin D and asthma. METHODS: This study included 29 mild and 30 moderate persistent asthma and 38 healthy control group. Evaluation of the three groups was carried out in respect of serum vitamin D levels, Respiratory Function Test (RFT), and Exercise Provocation Test (EPT). The two asthma groups were also examined using the Asthma Control Test (ACT) and Nitric Oxide in Exhaled Breath (FeNO) level. RESULTS: The vitamin D levels of the mild and the moderate persistent asthma groups were determined to be lower than the vitamin D levels of the control group (p=0.007). A significant negative correlation was determined in all cases between the vitamin D levels and the broncho-reversibility percentage (p=0.0002). The negative correlation between the vitamin D levels and the broncho-reversibility percentage was more evident in the moderate persistent asthma group (p=0.0001). In the moderate persistent asthma group, a significant positive correlation was determined between the lowness of the maximum forced expiratory volume in EPT and a low vitamin D level (p=0.009). The ACT scores were lower, and the FeNO levels were higher in the moderate asthma group compared to the mild asthma group (p=0.0001). CONCLUSION: The findings showed that low serum vitamin D levels were observed more often in children with asthma, and there was a correlation with increased broncho-reversibility in the RFT and increased bronchial hyper-reactivity in the EPT.

Most children who are allergic to cow's milk tolerate yogurt.

OBJECTIVE: Cow's milk allergy is the most common food allergy in childhood. Changes occur in the protein structure of milk during yogurt fermentation. This study aimed to determine whether children who are diagnosed with a cow's milk allergy can tolerate yogurt. METHODS: We performed a yogurt challenge test on 34 children who were diagnosed with a cow's milk allergy in our Pediatric Allergy Outpatient Clinic. The mean age of 24 male and 10 female children was 24 ± 13 months. RESULTS: A reaction was observed in 17 (50%) patients, whereas no reaction was observed in the other 17 (50%) during an oral yogurt challenge test that was performed in all of the 34 patients with a cow's milk allergy. Cow's milk-specific immunoglobulin E levels were significantly lower in the group of children who could tolerate yogurt than in the group of children who could not tolerate yogurt. CONCLUSION: Yogurt is tolerated by half of children with a cow's milk allergy when subjected to a challenge test performed with yogurt, which is consumed as much as milk in Turkey.

Genetic associations of the response to inhaled corticosteroids in children during an asthma exacerbation.

BACKGROUND: Genetic associations of the response to inhaled corticosteroids (ICSs) during an asthma exacerbation are unknown. OBJECTIVE: To evaluate the role of genetic variants in the therapeutic response to high-dose ICS in children with moderate-to-severe asthma exacerbations. METHODS: Eighty-two children (56 boys/26 girls, mean age 9.6 ± 3.2 years) with moderate-severe asthma exacerbation were genotyped for eight single-nucleotide polymorphisms that were a priori associated with ICS response in chronic asthma treatment: glucocorticosteroid receptor (NR3C1) rs41423247; corticotrophin-releasing hormone receptor1 (CRHR1) rs242939, rs242941, and rs1876828; T-box 21 (TBX21) rs2240017; glucocorticoid-induced transcript 1 (GLCCl1); and T gene rs3099266 and rs2305089. Children were treated with a single high-dose (4000 µg) fluticasone propionate given by a nebulizer followed by 1000 µg/day of inhaled fluticasone propionate for 6 days. Primary outcome measure was the improvement in FEV1 at 4 h. RESULTS: Mean FEV1 was 71.7 ± 14.2% at presentation. Overall, fluticasone treatment resulted in a significant improvement in asthma score and FEV1 (p < 0.0001 for both). Children with the GG genotype at NR3C1 rs41423247 (n = 26) had a higher improvement in FEV1 [24.2% (interquartile range 11.5-36.3)] compared to those with CG+CC (n = 19), [7.9% (interquartile range 6.1-24.6) (p = 0.006)]. CONCLUSION: Homozygosity for the G allele at rs41423247 of the glucocorticosteroid receptor (NR3C1) gene is associated with a higher improvement in FEV1 at 4 h in children with moderate-to-severe asthma exacerbation treated with high-dose ICS. This observation may have important clinical implications especially for children who use systemic steroids frequently for recurrent asthma exacerbations.

Exhaled RANTES and interleukin 4 levels after exercise challenge in children with asthma.

BACKGROUND: Despite the universality and clinical significance of exercise-induced bronchospasm (EIB), the mechanisms responsible for it are incompletely understood. OBJECTIVE: To investigate the role of exhaled RANTES (regulated on activation, normal T-cell expressed and secreted) and interleukin (IL) 4 in EIB in children with asthma. METHODS: Fifty-six children with asthma were evaluated with exercise challenge and exhaled RANTES and IL-4 levels. Exhaled breath condensate was collected before and 30 minutes after exercise challenge. RANTES and IL-4 concentrations were determined using a specific immunoassay kit. RESULTS: A significant increase was found in RANTES levels after exercise challenge in the asthmatic children (P<.001). A statistically significant increase in RANTES levels was noted after exercise challenge in both the asthmatic children with EIB (n=25, P=.007) and in the non-EIB asthmatic group (n=31, P=.005). Our study revealed that exhaled RANTES level correlates significantly well with percentage of forced expiratory volume in 1 second (FEV1), exacerbation frequency, serum IgE, and body mass index. No statistically significant increase was found in IL-4 levels after exercise challenge. The maximal postexercise decrease in FEV1 strongly correlated with total eosinophil count (P<.001, r = -0.61) and baseline ratio of FEV1 to forced vital capacity (FVC) (P=.002, r=0.40). Results from multivariate regression analysis adjusted for age, sex, and atopy as covariates showed that eosinophil count and FEV1/FVC ratio were significantly associated with EIB. CONCLUSION: We found that exercise challenge, leading to hyperosmolar stimulus, may increase exhaled RANTES levels in children with asthma. In addition, exhaled RANTES levels correlate well with serum IgE, severity of asthma, FEV1/FVC ratio, and body mass index. RANTES and IL-4 may not be independent predictors for EIB. Furthermore, eosinophil count and FEV1/FVC ratio may predict the presence and severity of EIB in asthmatic children.

Unusual presentation: pulmonary hemosiderosis with celiac disease and retinitis pigmentosa in a child.

Idiopathic pulmonary hemosiderosis (IPH) is a rare disease characterized by anemia, hemoptysis and recurrent alveolar hemorrhage. The combination of IPH and celiac disease (CD) is extremely rare. We report a 9-year-old boy with Lane-Hamilton syndrome, co-occurrence of pulmonary hemosiderosis with CD. This presentation is unique presentation because he has also retinal pigmentation.

Defects along the T(H)17 differentiation pathway underlie genetically distinct forms of the hyper IgE syndrome.

BACKGROUND: The hyper IgE syndrome (HIES) is characterized by abscesses, eczema, recurrent infections, skeletal and connective tissue abnormalities, elevated serum IgE, and diminished inflammatory responses. It exists as autosomal-dominant and autosomal-recessive forms that manifest common and distinguishing clinical features. A majority of those with autosomal-dominant HIES have heterozygous mutations in signal transducer and activator of transcription (STAT)-3 and impaired T(H)17 differentiation. OBJECTIVE: To elucidate mechanisms underlying different forms of HIES. METHODS: A cohort of 25 Turkish children diagnosed with HIES were examined for STAT3 mutations by DNA sequencing. Activation of STAT3 by IL-6 and IL-21 and STAT1 by IFN-alpha was assessed by intracellular staining with anti-phospho (p)STAT3 and -pSTAT1 antibodies. T(H)17 and T(H)1 cell differentiation was assessed by measuring the production of IL-17 and IFN-gamma, respectively. RESULTS: Six subjects had STAT3 mutations affecting the DNA binding, Src homology 2, and transactivation domains, including 3 novel ones. Mutation-positive but not mutation-negative subjects with HIES exhibited reduced phosphorylation of STAT3 in response to cytokine stimulation, whereas pSTAT1 activation was unaffected. Both patient groups exhibited impaired T(H)17 responses, but whereas STAT3 mutations abrogated early steps in T(H)17 differentiation, the defects in patients with HIES with normal STAT3 affected more distal steps. CONCLUSION: In this cohort of Turkish children with HIES, a majority had normal STAT3, implicating other targets in disease pathogenesis. Impaired T(H)17 responses were evident irrespective of the STAT3 mutation status, indicating that different genetic forms of HIES share a common functional outcome.

Association between previous enterobiasis and current wheezing: evaluation of 1018 children.

The aim of this study was to investigate the association between parasitosis and allergy. We surveyed all children aged 4-12 years living in poor hygienic conditions in a shantytown of Istanbul. After obtaining data from the International Study of Asthma and Allergies in Childhood (ISAAC) and an additional questionnaire, performing a skin-prick test (SPT), and determining total IgE, stool and perianal tape specimens were obtained from 1018 participating children. The prevalence of past episodes of wheezing, current wheezing, asthma, and rhinitis was 31, 14.6, 10.7, and 26.2%, respectively. Parasitosis was present in 49.1%, Enterobius vermicularis (23.3%), being the most common. A history of treatment for enterobiasis was present in 37%. Comparison of children with and without current enterobiasis revealed no significant difference in allergic manifestations and SPT results, except for serum total IgE level (p = 0.018), whereas children with previous enterobiasis were more likely to have current wheezing (p = 0.012). Current wheezers were more likely to have previous enterobiasis (p = 0.01) and a higher maternal employment level (p = 0.036) when compared with those without. According to logistic regression analysis, covariables significantly positively related with current wheezing were previous enterobiasis (p = 0.003) and being < or =5 years of age (p = 0.043), whereas being the first child of the family (p = 0.043) was negatively related. A previous infection with E. vermicularis was found to potentiate current wheezing in a population living in a shantytown in Istanbul.